I'm growing some citrus trees this year. I got into the project on a whim, but now I'm hooked.
The trees will never go in the ground. It is too cold and the soil pH is all wrong. Here in north Texas, I've got plenty of rain, sun and heat but my soil has a pH of 8+ (citrus requires 6-6.5) and there are about 75 nights of freezing weather each year (citrus can only stand a few hours of freezing weather each year). The ground is solid limestone or lime-sand.
Thus, I'm a container bound citrus grower. Most citrus growers use the ground, so there is very little on long term management of citrus in containers. The more I think about 'container management,' the more often hydroponics comes to mind. It seems hydroponics as a practice has a lot to offer.
So, I've started reading about hydroponics growing. I've got a copy of 'Gardening Indoors' by Van Patten. I've gone through many hydroponic websites and looked at things for sale on ebay.
I have not seen anything on plants that are expected to live for 20 years, or grow to heights of 10 to 15 feet.
At the present, I'm thinking about using modified platic trash barrels with perlite/gravel for medium. I suspect I could use a 'Dutch Pot' scheme, but may misunderstand the concept. The trees would get a greenhouse cover from November to March, but be outside the rest of the year. I've got a 1500 gal water tank for collect rain water.
Anyone have references or pointers?